ARB RD149 - Manual (Page 15)

3 Installing the Air Locker
13
3.5 Setting the Backlash
Assemble the remaining bearing cup onto the right-hand side of the
Air Locker.
Loosen the adjuster nuts in the housing so that they are as far apart
as possible.
Insert the Air Locker into the housing and rotate it until it is fully in
mesh with the pinion gear, with the seal housing tube pointing
straight out of the housing.
Hand tighten both adjuster nuts against the Air Locker until only a
small amount of backlash can be felt.
Install the bearing caps (use the markings from Section 2.4 to
determine which side is which) and hand tighten all bearing cap
bolts lightly.
Set a depth indicator on one of the ring gear teeth as in
Figure 8.
While supporting the pinion gear by holding the drive shaft, rotate
the differential in both directions while observing the maximum
variation in depth from the indicator (i.e., the highest value minus
the lowest value). This value is referred to as the ring and pinion
backlash.
Rotate the differential center 90
° and measure again for accuracy.
Figure 8.
Refer to your vehicle service manual for the specified maximum
and minimum amounts of backlash.